add

1 files changed, 1252 insertions, 0 deletions

diff --git a/src/cmd/file.c b/src/cmd/file.c
new file mode 100644
index 00000000..f09977b1
--- /dev/null
+++ b/src/cmd/file.c
@@ -0,0 +1,1252 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <ctype.h>
+#include <mach.h>
+
+/*
+ * file - determine type of file
+ */
+#define	LENDIAN(p)	((p)[0] | ((p)[1]<<8) | ((p)[2]<<16) | ((p)[3]<<24))
+
+uchar	buf[6001];
+short	cfreq[140];
+short	wfreq[50];
+int	nbuf;
+Dir*	mbuf;
+int	fd;
+char 	*fname;
+char	*slash;
+
+enum
+{
+	Cword,
+	Fword,
+	Aword,
+	Alword,
+	Lword,
+	I1,
+	I2,
+	I3,
+	Clatin	= 128,
+	Cbinary,
+	Cnull,
+	Ceascii,
+	Cutf,
+};
+struct
+{
+	char*	word;
+	int	class;
+} dict[] =
+{
+	"PATH",		Lword,
+	"TEXT",		Aword,
+	"adt",		Alword,
+	"aggr",		Alword,
+	"alef",		Alword,
+	"array",	Lword,
+	"block",	Fword,
+	"chan",		Alword,
+	"char",		Cword,
+	"common",	Fword,
+	"con",		Lword,
+	"data",		Fword,
+	"dimension",	Fword,	
+	"double",	Cword,
+	"extern",	Cword,
+	"bio",		I2,
+	"float",	Cword,
+	"fn",		Lword,
+	"function",	Fword,
+	"h",		I3,
+	"implement",	Lword,
+	"import",	Lword,
+	"include",	I1,
+	"int",		Cword,
+	"integer",	Fword,
+	"iota",		Lword,
+	"libc",		I2,
+	"long",		Cword,
+	"module",	Lword,
+	"real",		Fword,
+	"ref",		Lword,
+	"register",	Cword,
+	"self",		Lword,
+	"short",	Cword,
+	"static",	Cword,
+	"stdio",	I2,
+	"struct",	Cword,
+	"subroutine",	Fword,
+	"u",		I2,
+	"void",		Cword,
+};
+
+/* codes for 'mode' field in language structure */
+enum	{
+		Normal	= 0,
+		First,		/* first entry for language spanning several ranges */
+		Multi,		/* later entries "   "       "  ... */ 
+		Shared,		/* codes used in several languages */
+	};
+
+struct
+{
+	int	mode;		/* see enum above */
+	int 	count;
+	int	low;
+	int	high;
+	char	*name;
+	
+} language[] =
+{
+	Normal, 0,	0x0080, 0x0080,	"Extended Latin",
+	Normal,	0,	0x0100,	0x01FF,	"Extended Latin",
+	Normal,	0,	0x0370,	0x03FF,	"Greek",
+	Normal,	0,	0x0400,	0x04FF,	"Cyrillic",
+	Normal,	0,	0x0530,	0x058F,	"Armenian",
+	Normal,	0,	0x0590,	0x05FF,	"Hebrew",
+	Normal,	0,	0x0600,	0x06FF,	"Arabic",
+	Normal,	0,	0x0900,	0x097F,	"Devanagari",
+	Normal,	0,	0x0980,	0x09FF,	"Bengali",
+	Normal,	0,	0x0A00,	0x0A7F,	"Gurmukhi",
+	Normal,	0,	0x0A80,	0x0AFF,	"Gujarati",
+	Normal,	0,	0x0B00,	0x0B7F,	"Oriya",
+	Normal,	0,	0x0B80,	0x0BFF,	"Tamil",
+	Normal,	0,	0x0C00,	0x0C7F,	"Telugu",
+	Normal,	0,	0x0C80,	0x0CFF,	"Kannada",
+	Normal,	0,	0x0D00,	0x0D7F,	"Malayalam",
+	Normal,	0,	0x0E00,	0x0E7F,	"Thai",
+	Normal,	0,	0x0E80,	0x0EFF,	"Lao",
+	Normal,	0,	0x1000,	0x105F,	"Tibetan",
+	Normal,	0,	0x10A0,	0x10FF,	"Georgian",
+	Normal,	0,	0x3040,	0x30FF,	"Japanese",
+	Normal,	0,	0x3100,	0x312F,	"Chinese",
+	First,	0,	0x3130,	0x318F,	"Korean",
+	Multi,	0,	0x3400,	0x3D2F,	"Korean",
+	Shared,	0,	0x4e00,	0x9fff,	"CJK",
+	Normal,	0,	0,	0,	0,		/* terminal entry */
+};
+	
+	
+enum
+{
+	Fascii,		/* printable ascii */
+	Flatin,		/* latin 1*/
+	Futf,		/* UTf character set */
+	Fbinary,	/* binary */
+	Feascii,	/* ASCII with control chars */
+	Fnull,		/* NULL in file */
+} guess;
+
+void	bump_utf_count(Rune);
+int	cistrncmp(char*, char*, int);
+void	filetype(int);
+int	getfontnum(uchar*, uchar**);
+int	isas(void);
+int	isc(void);
+int	isenglish(void);
+int	ishp(void);
+int	ishtml(void);
+int	isrfc822(void);
+int	ismbox(void);
+int	islimbo(void);
+int	ismung(void);
+int	isp9bit(void);
+int	isp9font(void);
+int	isrtf(void);
+int	ismsdos(void);
+int	iself(void);
+int	istring(void);
+int	iff(void);
+int	long0(void);
+int	istar(void);
+int	p9bitnum(uchar*);
+int	p9subfont(uchar*);
+void	print_utf(void);
+void	type(char*, int);
+int	utf_count(void);
+void	wordfreq(void);
+
+int	(*call[])(void) =
+{
+	long0,		/* recognizable by first 4 bytes */
+	istring,	/* recognizable by first string */
+	iff,		/* interchange file format (strings) */
+	isrfc822,	/* email file */
+	ismbox,		/* mail box */
+	istar,		/* recognizable by tar checksum */
+	ishtml,		/* html keywords */
+/*	iscint,		/* compiler/assembler intermediate */
+	islimbo,	/* limbo source */
+	isc,		/* c & alef compiler key words */
+	isas,		/* assembler key words */
+	ismung,		/* entropy compressed/encrypted */
+	isp9font,	/* plan 9 font */
+	isp9bit,	/* plan 9 image (as from /dev/window) */
+	isenglish,	/* char frequency English */
+	isrtf,		/* rich text format */
+	ismsdos,	/* msdos exe (virus file attachement) */
+	iself,		/* ELF (foreign) executable */
+	0
+};
+
+int mime;
+
+#define OCTET	"application/octet-stream\n"
+#define PLAIN	"text/plain\n"
+
+void
+main(int argc, char *argv[])
+{
+	int i, j, maxlen;
+	char *cp;
+	Rune r;
+
+	ARGBEGIN{
+	case 'm':
+		mime = 1;
+		break;
+	default:
+		fprint(2, "usage: file [-m] [file...]\n");
+		exits("usage");
+	}ARGEND;
+
+	maxlen = 0;
+	if(mime == 0 || argc > 1){
+		for(i = 0; i < argc; i++) {
+			for (j = 0, cp = argv[i]; *cp; j++, cp += chartorune(&r, cp))
+					;
+			if(j > maxlen)
+				maxlen = j;
+		}
+	}
+	if (argc <= 0) {
+		if(!mime)
+			print ("stdin: ");
+		filetype(0);
+	}
+	else {
+		for(i = 0; i < argc; i++)
+			type(argv[i], maxlen);
+	}
+	exits(0);
+}
+
+void
+type(char *file, int nlen)
+{
+	Rune r;
+	int i;
+	char *p;
+
+	if(nlen > 0){
+		slash = 0;
+		for (i = 0, p = file; *p; i++) {
+			if (*p == '/')			/* find rightmost slash */
+				slash = p;
+			p += chartorune(&r, p);		/* count runes */
+		}
+		print("%s:%*s",file, nlen-i+1, "");
+	}
+	fname = file;
+	if ((fd = open(file, OREAD)) < 0) {
+		print("cannot open\n");
+		return;
+	}
+	filetype(fd);
+	close(fd);
+}
+
+void
+filetype(int fd)
+{
+	Rune r;
+	int i, f, n;
+	char *p, *eob;
+
+	free(mbuf);
+	mbuf = dirfstat(fd);
+	if(mbuf == nil){
+		print("cannot stat: %r\n");
+		return;
+	}
+	if(mbuf->mode & DMDIR) {
+		print(mime ? "text/directory\n" : "directory\n");
+		return;
+	}
+	if(mbuf->type != 'M' && mbuf->type != '|') {
+		print(mime ? OCTET : "special file #%c/%s\n",
+			mbuf->type, mbuf->name);
+		return;
+	}
+	nbuf = read(fd, buf, sizeof(buf)-1);
+
+	if(nbuf < 0) {
+		print("cannot read\n");
+		return;
+	}
+	if(nbuf == 0) {
+		print(mime ? PLAIN : "empty file\n");
+		return;
+	}
+	buf[nbuf] = 0;
+
+	/*
+	 * build histogram table
+	 */
+	memset(cfreq, 0, sizeof(cfreq));
+	for (i = 0; language[i].name; i++)
+		language[i].count = 0;
+	eob = (char *)buf+nbuf;
+	for(n = 0, p = (char *)buf; p < eob; n++) {
+		if (!fullrune(p, eob-p) && eob-p < UTFmax)
+			break;
+		p += chartorune(&r, p);
+		if (r == 0)
+			f = Cnull;
+		else if (r <= 0x7f) {
+			if (!isprint(r) && !isspace(r))
+				f = Ceascii;	/* ASCII control char */
+			else f = r;
+		} else if (r == 0x080) {
+			bump_utf_count(r);
+			f = Cutf;
+		} else if (r < 0xA0)
+				f = Cbinary;	/* Invalid Runes */
+		else if (r <= 0xff)
+				f = Clatin;	/* Latin 1 */
+		else {
+			bump_utf_count(r);
+			f = Cutf;		/* UTF extension */
+		}
+		cfreq[f]++;			/* ASCII chars peg directly */
+	}
+	/*
+	 * gross classify
+	 */
+	if (cfreq[Cbinary])
+		guess = Fbinary;
+	else if (cfreq[Cutf])
+		guess = Futf;
+	else if (cfreq[Clatin])
+		guess = Flatin;
+	else if (cfreq[Ceascii])
+		guess = Feascii;
+	else if (cfreq[Cnull] == n) {
+		print(mime ? OCTET : "first block all null bytes\n");
+		return;
+	}
+	else guess = Fascii;
+	/*
+	 * lookup dictionary words
+	 */
+	memset(wfreq, 0, sizeof(wfreq));
+	if(guess == Fascii || guess == Flatin || guess == Futf) 
+		wordfreq();
+	/*
+	 * call individual classify routines
+	 */
+	for(i=0; call[i]; i++)
+		if((*call[i])())
+			return;
+
+	/*
+	 * if all else fails,
+	 * print out gross classification
+	 */
+	if (nbuf < 100 && !mime)
+		print(mime ? PLAIN : "short ");
+	if (guess == Fascii)
+		print(mime ? PLAIN : "Ascii\n");
+	else if (guess == Feascii)
+		print(mime ? PLAIN : "extended ascii\n");
+	else if (guess == Flatin)
+		print(mime ? PLAIN : "latin ascii\n");
+	else if (guess == Futf && utf_count() < 4)
+		print_utf();
+	else print(mime ? OCTET : "binary\n");
+}
+
+void
+bump_utf_count(Rune r)
+{
+	int low, high, mid;
+
+	high = sizeof(language)/sizeof(language[0])-1;
+	for (low = 0; low < high;) {
+		mid = (low+high)/2;
+		if (r >=language[mid].low) {
+			if (r <= language[mid].high) {
+				language[mid].count++;
+				break;
+			} else low = mid+1;
+		} else high = mid;
+	}
+}
+
+int
+utf_count(void)
+{
+	int i, count;
+
+	count = 0;
+	for (i = 0; language[i].name; i++)
+		if (language[i].count > 0)
+			switch (language[i].mode) {
+			case Normal:
+			case First:
+				count++;
+				break;
+			default:
+				break;
+			}
+	return count;
+}
+
+int
+chkascii(void)
+{
+	int i;
+
+	for (i = 'a'; i < 'z'; i++)
+		if (cfreq[i])
+			return 1;
+	for (i = 'A'; i < 'Z'; i++)
+		if (cfreq[i])
+			return 1;
+	return 0;
+}
+
+int
+find_first(char *name)
+{
+	int i;
+
+	for (i = 0; language[i].name != 0; i++)
+		if (language[i].mode == First
+			&& strcmp(language[i].name, name) == 0)
+			return i;
+	return -1;
+}
+
+void
+print_utf(void)
+{
+	int i, printed, j;
+
+	if(mime){
+		print(PLAIN);
+		return;
+	}
+	if (chkascii()) {
+		printed = 1;
+		print("Ascii");
+	} else
+		printed = 0;
+	for (i = 0; language[i].name; i++)
+		if (language[i].count) {
+			switch(language[i].mode) {
+			case Multi:
+				j = find_first(language[i].name);
+				if (j < 0)
+					break;
+				if (language[j].count > 0)
+					break;
+				/* Fall through */
+			case Normal:
+			case First:
+				if (printed)
+					print(" & ");
+				else printed = 1;
+				print("%s", language[i].name);
+				break;
+			case Shared:
+			default:
+				break;
+			}
+		}
+	if(!printed)
+		print("UTF");
+	print(" text\n");
+}
+
+void
+wordfreq(void)
+{
+	int low, high, mid, r;
+	uchar *p, *p2, c;
+
+	p = buf;
+	for(;;) {
+		while (p < buf+nbuf && !isalpha(*p))
+			p++;
+		if (p >= buf+nbuf)
+			return;
+		p2 = p;
+		while(p < buf+nbuf && isalpha(*p))
+			p++;
+		c = *p;
+		*p = 0;
+		high = sizeof(dict)/sizeof(dict[0]);
+		for(low = 0;low < high;) {
+			mid = (low+high)/2;
+			r = strcmp(dict[mid].word, (char*)p2);
+			if(r == 0) {
+				wfreq[dict[mid].class]++;
+				break;
+			}
+			if(r < 0)
+				low = mid+1;
+			else
+				high = mid;
+		}
+		*p++ = c;
+	}
+}
+
+typedef struct Filemagic Filemagic;
+struct Filemagic {
+	ulong x;
+	ulong mask;
+	char *desc;
+	char *mime;
+};
+
+Filemagic long0tab[] = {
+	0xF16DF16D,	0xFFFFFFFF,	"pac1 audio file\n",	OCTET,
+	0x31636170,	0xFFFFFFFF,	"pac3 audio file\n",	OCTET,
+	0x32636170,	0xFFFF00FF,	"pac4 audio file\n",	OCTET,
+	0xBA010000,	0xFFFFFFFF,	"mpeg system stream\n",	OCTET,
+	0x30800CC0,	0xFFFFFFFF,	"inferno .dis executable\n", OCTET,
+	0x04034B50,	0xFFFFFFFF,	"zip archive\n", "application/zip",
+	070707,		0xFFFF,		"cpio archive\n", OCTET,
+	0x2F7,		0xFFFF,		"tex dvi\n", "application/dvi",
+	0xfffa0000,	0xfffe0000,	"mp3 audio",	"audio/mpeg",
+};
+
+int
+filemagic(Filemagic *tab, int ntab, ulong x)
+{
+	int i;
+
+	for(i=0; i<ntab; i++)
+		if((x&tab[i].mask) == tab[i].x){
+			print(mime ? tab[i].mime : tab[i].desc);
+			return 1;
+		}
+	return 0;
+}
+	
+int
+long0(void)
+{
+//	Fhdr *f;
+	long x;
+
+	seek(fd, 0, 0);		/* reposition to start of file */
+/*
+	if(crackhdr(fd, &f)) {
+		print(mime ? OCTET : "%s\n", f.name);
+		return 1;
+	}
+*/
+	x = LENDIAN(buf);
+	if(filemagic(long0tab, nelem(long0tab), x))
+		return 1;
+	return 0;
+}
+
+/* from tar.c */
+enum { NAMSIZ = 100, TBLOCK = 512 };
+
+union	hblock
+{
+	char	dummy[TBLOCK];
+	struct	header
+	{
+		char	name[NAMSIZ];
+		char	mode[8];
+		char	uid[8];
+		char	gid[8];
+		char	size[12];
+		char	mtime[12];
+		char	chksum[8];
+		char	linkflag;
+		char	linkname[NAMSIZ];
+		/* rest are defined by POSIX's ustar format; see p1003.2b */
+		char	magic[6];	/* "ustar" */
+		char	version[2];
+		char	uname[32];
+		char	gname[32];
+		char	devmajor[8];
+		char	devminor[8];
+		char	prefix[155];  /* if non-null, path = prefix "/" name */
+	} dbuf;
+};
+
+int
+checksum(union hblock *hp)
+{
+	int i;
+	char *cp;
+	struct header *hdr = &hp->dbuf;
+
+	for (cp = hdr->chksum; cp < &hdr->chksum[sizeof hdr->chksum]; cp++)
+		*cp = ' ';
+	i = 0;
+	for (cp = hp->dummy; cp < &hp->dummy[TBLOCK]; cp++)
+		i += *cp & 0xff;
+	return i;
+}
+
+int
+istar(void)
+{
+	int chksum;
+	char tblock[TBLOCK];
+	union hblock *hp = (union hblock *)tblock;
+	struct header *hdr = &hp->dbuf;
+
+	seek(fd, 0, 0);		/* reposition to start of file */
+	if (readn(fd, tblock, sizeof tblock) != sizeof tblock)
+		return 0;
+	chksum = strtol(hdr->chksum, 0, 8);
+	if (hdr->name[0] != '\0' && checksum(hp) == chksum) {
+		if (strcmp(hdr->magic, "ustar") == 0)
+			print(mime? "application/x-ustar\n":
+				"posix tar archive\n");
+		else
+			print(mime? "application/x-tar\n": "tar archive\n");
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * initial words to classify file
+ */
+struct	FILE_STRING
+{
+	char 	*key;
+	char	*filetype;
+	int	length;
+	char	*mime;
+} file_string[] =
+{
+	"!<arch>\n__.SYMDEF",	"archive random library",	16,	"application/octet-stream",
+	"!<arch>\n",		"archive",			8,	"application/octet-stream",
+	"070707",		"cpio archive - ascii header",	6,	"application/octet-stream",
+	"#!/bin/rc",		"rc executable file",		9,	"text/plain",
+	"#!/bin/sh",		"sh executable file",		9,	"text/plain",
+	"%!",			"postscript",			2,	"application/postscript",
+	"\004%!",		"postscript",			3,	"application/postscript",
+	"x T post",		"troff output for post",	8,	"application/troff",
+	"x T Latin1",		"troff output for Latin1",	10,	"application/troff",
+	"x T utf",		"troff output for UTF",		7,	"application/troff",
+	"x T 202",		"troff output for 202",		7,	"application/troff",
+	"x T aps",		"troff output for aps",		7,	"application/troff",
+	"GIF",			"GIF image", 			3,	"image/gif",
+	"\0PC Research, Inc\0",	"ghostscript fax file",		18,	"application/ghostscript",
+	"%PDF",			"PDF",				4,	"application/pdf",
+	"<html>\n",		"HTML file",			7,	"text/html",
+	"<HTML>\n",		"HTML file",			7,	"text/html",
+	"compressed\n",		"Compressed image or subfont",	11,	"application/octet-stream",
+	"\111\111\052\000",	"tiff",				4,	"image/tiff",
+	"\115\115\000\052",	"tiff",				4,	"image/tiff",
+	"\377\330\377\340",	"jpeg",				4,	"image/jpeg",
+	"\377\330\377\341",	"jpeg",				4,	"image/jpeg",
+	"\377\330\377\333",	"jpeg",				4,	"image/jpeg",
+	"BM",			"bmp",				2,	"image/bmp",
+	"\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1",	"microsoft office document",	8,	"application/octet-stream",
+	"<MakerFile ",		"FrameMaker file",		11,	"application/framemaker",
+	"\033%-12345X",	"HPJCL file",		9,	"application/hpjcl",
+	"ID3",			"mp3 audio with id3",	3,	"audio/mpeg",
+	0,0,0,0
+};
+
+int
+istring(void)
+{
+	int i;
+	struct FILE_STRING *p;
+
+	for(p = file_string; p->key; p++) {
+		if(nbuf >= p->length && !memcmp(buf, p->key, p->length)) {
+			if(mime)
+				print("%s\n", p->mime);
+			else
+				print("%s\n", p->filetype);
+			return 1;
+		}
+	}
+	if(strncmp((char*)buf, "TYPE=", 5) == 0) {	/* td */
+		for(i = 5; i < nbuf; i++)
+			if(buf[i] == '\n')
+				break;
+		if(mime)
+			print(OCTET);
+		else
+			print("%.*s picture\n", utfnlen((char*)buf+5, i-5), (char*)buf+5);
+		return 1;
+	}
+	return 0;
+}
+
+int
+iff(void)
+{
+	if (strncmp((char*)buf, "FORM", 4) == 0 &&
+	    strncmp((char*)buf+8, "AIFF", 4) == 0) {
+		print("%s\n", mime? "audio/x-aiff": "aiff audio");
+		return 1;
+	}
+	return 0;
+}
+
+char*	html_string[] =
+{
+	"title",
+	"body",
+	"head",
+	"strong",
+	"h1",
+	"h2",
+	"h3",
+	"h4",
+	"h5",
+	"h6",
+	"ul",
+	"li",
+	"dl",
+	"br",
+	"em",
+	0,
+};
+
+int
+ishtml(void)
+{
+	uchar *p, *q;
+	int i, count;
+
+		/* compare strings between '<' and '>' to html table */
+	count = 0;
+	p = buf;
+	for(;;) {
+		while (p < buf+nbuf && *p != '<')
+			p++;
+		p++;
+		if (p >= buf+nbuf)
+			break;
+		if(*p == '/')
+			p++;
+		q = p;
+		while(p < buf+nbuf && *p != '>')
+			p++;
+		if (p >= buf+nbuf)
+			break;
+		for(i = 0; html_string[i]; i++) {
+			if(cistrncmp(html_string[i], (char*)q, p-q) == 0) {
+				if(count++ > 4) {
+					print(mime ? "text/html\n" : "HTML file\n");
+					return 1;
+				}
+				break;
+			}
+		}
+		p++;
+	}
+	return 0;
+}
+
+char*	rfc822_string[] =
+{
+	"from:",
+	"date:",
+	"to:",
+	"subject:",
+	"received:",
+	"reply to:",
+	"sender:",
+	0,
+};
+
+int
+isrfc822(void)
+{
+
+	char *p, *q, *r;
+	int i, count;
+
+	count = 0;
+	p = (char*)buf;
+	for(;;) {
+		q = strchr(p, '\n');
+		if(q == nil)
+			break;
+		*q = 0;
+		if(p == (char*)buf && strncmp(p, "From ", 5) == 0 && strstr(p, " remote from ")){
+			count++;
+			*q = '\n';
+			p = q+1;
+			continue;
+		}
+		*q = '\n';
+		if(*p != '\t' && *p != ' '){
+			r = strchr(p, ':');
+			if(r == 0 || r > q)
+				break;
+			for(i = 0; rfc822_string[i]; i++) {
+				if(cistrncmp(p, rfc822_string[i], strlen(rfc822_string[i])) == 0){
+					count++;
+					break;
+				}
+			}
+		}
+		p = q+1;
+	}
+	if(count >= 3){
+		print(mime ? "message/rfc822\n" : "email file\n");
+		return 1;
+	}
+	return 0;
+}
+
+int
+ismbox(void)
+{
+	char *p, *q;
+
+	p = (char*)buf;
+	q = strchr(p, '\n');
+	if(q == nil)
+		return 0;
+	*q = 0;
+	if(strncmp(p, "From ", 5) == 0 && strstr(p, " remote from ") == nil){
+		print(mime ? "text/plain\n" : "mail box\n");
+		return 1;
+	}
+	*q = '\n';
+	return 0;
+}
+
+int
+isc(void)
+{
+	int n;
+
+	n = wfreq[I1];
+	/*
+	 * includes
+	 */
+	if(n >= 2 && wfreq[I2] >= n && wfreq[I3] >= n && cfreq['.'] >= n)
+		goto yes;
+	if(n >= 1 && wfreq[Alword] >= n && wfreq[I3] >= n && cfreq['.'] >= n)
+		goto yes;
+	/*
+	 * declarations
+	 */
+	if(wfreq[Cword] >= 5 && cfreq[';'] >= 5)
+		goto yes;
+	/*
+	 * assignments
+	 */
+	if(cfreq[';'] >= 10 && cfreq['='] >= 10 && wfreq[Cword] >= 1)
+		goto yes;
+	return 0;
+
+yes:
+	if(mime){
+		print(PLAIN);
+		return 1;
+	}
+	if(wfreq[Alword] > 0)
+		print("alef program\n");
+	else 
+		print("c program\n");
+	return 1;
+}
+
+int
+islimbo(void)
+{
+
+	/*
+	 * includes
+	 */
+	if(wfreq[Lword] < 4)
+		return 0;
+	print(mime ? PLAIN : "limbo program\n");
+	return 1;
+}
+
+int
+isas(void)
+{
+
+	/*
+	 * includes
+	 */
+	if(wfreq[Aword] < 2)
+		return 0;
+	print(mime ? PLAIN : "as program\n");
+	return 1;
+}
+
+/*
+ * low entropy means encrypted
+ */
+int
+ismung(void)
+{
+	int i, bucket[8];
+	float cs;
+
+	if(nbuf < 64)
+		return 0;
+	memset(bucket, 0, sizeof(bucket));
+	for(i=0; i<64; i++)
+		bucket[(buf[i]>>5)&07] += 1;
+
+	cs = 0.;
+	for(i=0; i<8; i++)
+		cs += (bucket[i]-8)*(bucket[i]-8);
+	cs /= 8.;
+	if(cs <= 24.322) {
+		if(buf[0]==0x1f && (buf[1]==0x8b || buf[1]==0x9d))
+			print(mime ? OCTET : "compressed\n");
+		else
+			print(mime ? OCTET : "encrypted\n");
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * english by punctuation and frequencies
+ */
+int
+isenglish(void)
+{
+	int vow, comm, rare, badpun, punct;
+	char *p;
+
+	if(guess != Fascii && guess != Feascii)
+		return 0;
+	badpun = 0;
+	punct = 0;
+	for(p = (char *)buf; p < (char *)buf+nbuf-1; p++)
+		switch(*p) {
+		case '.':
+		case ',':
+		case ')':
+		case '%':
+		case ';':
+		case ':':
+		case '?':
+			punct++;
+			if(p[1] != ' ' && p[1] != '\n')
+				badpun++;
+		}
+	if(badpun*5 > punct)
+		return 0;
+	if(cfreq['>']+cfreq['<']+cfreq['/'] > cfreq['e'])	/* shell file test */
+		return 0;
+	if(2*cfreq[';'] > cfreq['e'])
+		return 0;
+
+	vow = 0;
+	for(p="AEIOU"; *p; p++) {
+		vow += cfreq[*p];
+		vow += cfreq[tolower(*p)];
+	}
+	comm = 0;
+	for(p="ETAION"; *p; p++) {
+		comm += cfreq[*p];
+		comm += cfreq[tolower(*p)];
+	}
+	rare = 0;
+	for(p="VJKQXZ"; *p; p++) {
+		rare += cfreq[*p];
+		rare += cfreq[tolower(*p)];
+	}
+	if(vow*5 >= nbuf-cfreq[' '] && comm >= 10*rare) {
+		print(mime ? PLAIN : "English text\n");
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * pick up a number with
+ * syntax _*[0-9]+_
+ */
+#define	P9BITLEN	12
+int
+p9bitnum(uchar *bp)
+{
+	int n, c, len;
+
+	len = P9BITLEN;
+	while(*bp == ' ') {
+		bp++;
+		len--;
+		if(len <= 0)
+			return -1;
+	}
+	n = 0;
+	while(len > 1) {
+		c = *bp++;
+		if(!isdigit(c))
+			return -1;
+		n = n*10 + c-'0';
+		len--;
+	}
+	if(*bp != ' ')
+		return -1;
+	return n;
+}
+
+int
+depthof(char *s, int *newp)
+{
+	char *es;
+	int d;
+
+	*newp = 0;
+	es = s+12;
+	while(s<es && *s==' ')
+		s++;
+	if(s == es)
+		return -1;
+	if('0'<=*s && *s<='9')
+		return 1<<atoi(s);
+
+	*newp = 1;
+	d = 0;
+	while(s<es && *s!=' '){
+		s++;	/* skip letter */
+		d += strtoul(s, &s, 10);
+	}
+	
+	switch(d){
+	case 32:
+	case 24:
+	case 16:
+	case 8:
+		return d;
+	}
+	return -1;
+}
+
+int
+isp9bit(void)
+{
+	int dep, lox, loy, hix, hiy, px, new;
+	ulong t;
+	long len;
+	char *newlabel;
+
+	newlabel = "old ";
+
+	dep = depthof((char*)buf + 0*P9BITLEN, &new);
+	if(new)
+		newlabel = "";
+	lox = p9bitnum(buf + 1*P9BITLEN);
+	loy = p9bitnum(buf + 2*P9BITLEN);
+	hix = p9bitnum(buf + 3*P9BITLEN);
+	hiy = p9bitnum(buf + 4*P9BITLEN);
+	if(dep < 0 || lox < 0 || loy < 0 || hix < 0 || hiy < 0)
+		return 0;
+
+	if(dep < 8){
+		px = 8/dep;	/* pixels per byte */
+		/* set l to number of bytes of data per scan line */
+		if(lox >= 0)
+			len = (hix+px-1)/px - lox/px;
+		else{	/* make positive before divide */
+			t = (-lox)+px-1;
+			t = (t/px)*px;
+			len = (t+hix+px-1)/px;
+		}
+	}else
+		len = (hix-lox)*dep/8;
+	len *= (hiy-loy);		/* col length */
+	len += 5*P9BITLEN;		/* size of initial ascii */
+
+	/*
+	 * for image file, length is non-zero and must match calculation above
+	 * for /dev/window and /dev/screen the length is always zero
+	 * for subfont, the subfont header should follow immediately.
+	 */
+	if (len != 0 && mbuf->length == 0) {
+		print("%splan 9 image\n", newlabel);
+		return 1;
+	}
+	if (mbuf->length == len) {
+		print("%splan 9 image\n", newlabel);
+		return 1;
+	}
+	/* Ghostscript sometimes produces a little extra on the end */
+	if (mbuf->length < len+P9BITLEN) {
+		print("%splan 9 image\n", newlabel);
+		return 1;
+	}
+	if (p9subfont(buf+len)) {
+		print("%ssubfont file\n", newlabel);
+		return 1;
+	}
+	return 0;
+}
+
+int
+p9subfont(uchar *p)
+{
+	int n, h, a;
+
+		/* if image too big, assume it's a subfont */
+	if (p+3*P9BITLEN > buf+sizeof(buf))
+		return 1;
+
+	n = p9bitnum(p + 0*P9BITLEN);	/* char count */
+	if (n < 0)
+		return 0;
+	h = p9bitnum(p + 1*P9BITLEN);	/* height */
+	if (h < 0)
+		return 0;
+	a = p9bitnum(p + 2*P9BITLEN);	/* ascent */
+	if (a < 0)
+		return 0;
+	return 1;
+}
+
+#define	WHITESPACE(c)		((c) == ' ' || (c) == '\t' || (c) == '\n')
+
+int
+isp9font(void)
+{
+	uchar *cp, *p;
+	int i, n;
+	char pathname[1024];
+
+	cp = buf;
+	if (!getfontnum(cp, &cp))	/* height */
+		return 0;
+	if (!getfontnum(cp, &cp))	/* ascent */
+		return 0;
+	for (i = 0; 1; i++) {
+		if (!getfontnum(cp, &cp))	/* min */
+			break;
+		if (!getfontnum(cp, &cp))	/* max */
+			return 0;
+		while (WHITESPACE(*cp))
+			cp++;
+		for (p = cp; *cp && !WHITESPACE(*cp); cp++)
+				;
+			/* construct a path name, if needed */
+		n = 0;
+		if (*p != '/' && slash) {
+			n = slash-fname+1;
+			if (n < sizeof(pathname))
+				memcpy(pathname, fname, n);
+			else n = 0;
+		}
+		if (n+cp-p < sizeof(pathname)) {
+			memcpy(pathname+n, p, cp-p);
+			n += cp-p;
+			pathname[n] = 0;
+			if (access(pathname, AEXIST) < 0)
+				return 0;
+		}
+	}
+	if (i) {
+		print(mime ? "text/plain\n" : "font file\n");
+		return 1;
+	}
+	return 0;
+}
+
+int
+getfontnum(uchar *cp, uchar **rp)
+{
+	while (WHITESPACE(*cp))		/* extract ulong delimited by whitespace */
+		cp++;
+	if (*cp < '0' || *cp > '9')
+		return 0;
+	strtoul((char *)cp, (char **)rp, 0);
+	if (!WHITESPACE(**rp))
+		return 0;
+	return 1;
+}
+
+int
+isrtf(void)
+{
+	if(strstr((char *)buf, "\\rtf1")){
+		print(mime ? "application/rtf\n" : "rich text format\n");
+		return 1;
+	}
+	return 0;
+}
+
+int
+ismsdos(void)
+{
+	if (buf[0] == 0x4d && buf[1] == 0x5a){
+		print(mime ? "application/x-msdownload\n" : "MSDOS executable\n");
+		return 1;
+	}
+	return 0;
+}
+
+int
+iself(void)
+{
+	char *cpu[] = {		/* NB: incomplete and arbitary list */
+	[1]	"WE32100",
+	[2]	"SPARC",
+	[3]	"i386",
+	[4]	"M68000",
+	[5]	"M88000",
+	[6]	"i486",
+	[7]	"i860",
+	[8]	"R3000",
+	[9]	"S370",
+	[10]	"R4000",
+	[15]	"HP-PA",
+	[18]	"sparc v8+",
+	[19]	"i960",
+	[20]	"PPC-32",
+	[21]	"PPC-64",
+	[40]	"ARM",
+	[41]	"Alpha",
+	[43]	"sparc v9",
+	[50]	"IA-46",
+	[62]	"AMD64",
+	[75]	"VAX",
+	};
+
+
+	if (memcmp(buf, "\x7fELF", 4) == 0){
+		if (!mime){
+			int n = (buf[19] << 8) | buf[18];
+			char *p = "unknown";
+
+			if (n > 0 && n < nelem(cpu) && cpu[n])
+				p = cpu[n];
+			else {
+				/* try the other byte order */
+				n = (buf[18] << 8) | buf[19];
+				if (n > 0 && n < nelem(cpu) && cpu[n])
+					p = cpu[n];
+			}
+			print("%s ELF executable\n", p);
+		}
+		else
+			print("application/x-elf-executable");
+		return 1;
+	}
+
+	return 0;
+}